Deletion of upstream mediators of GDNF expression, such as Eya1, Pax2, and Gdf11, also results in renal agenesis (Xu et al., 1999; Bouchard et al., 2002; Esquela and Lee, 2003; Li et al., 2003; Brodbeck and Englert, 2004; Shah et al., 2004). The gene discussed is GDNF; the disease is renal agenesis.